This invention relates to electric machines, and more specifically to a synchronous disk type motor using an amorphous metal stator structure and a permanent magnet rotor which can also serve as an integral flywheel for the motor.
High efficiency motors which are driven by load commutated inverters are required particularly for applications such as direct wheel drives for electric vehicles, single motor drives for electric vehicles, and generally for motor/generator structures for cars and buses with an integrated flywheel.
Low cost magnetic materials and low loss high efficiency materials would be very desirable for use in such applications, and a disk type motor configuration would also be very desirable for these applications.
Amorphous metal tape having good magnetic properties has recently become available at about one-fourth the cost of conventional steels used in electric machines. These tapes exhibit a core loss about one-fourth that of the conventional silicon iron and have very high permeability. Amorphous metal tapes, however, are not available in the usual lamination form now needed for the construction of conventional electric machines so that the desirable magnetic properties and low cost of the amorphous metal glass has not been used for an electric machine. Presently available tape is made very thin (of from 0.0005 to 0.003 inch thick) and in widths of up to about two inches this time.
Amorphous metal tapes having magnetic properties desired for application to electric machines are disclosed in U.S. Pat. Nos. 3,856,513, dated Dec. 24, 1974, in the name of Chen et al.; 3,881,542, dated May 6, 1975, in the name of Polk et al.; 4,052,201, dated Oct. 4, 1977, in the name of Polk et al.; 4,059,441, dated Nov. 22, 1977, in the name of Ray. A survey of metal glass technology is given in the article "Metallic Glasses" by John J. Gilman appearing in Physics Today, May 1975, pages 46 to 53. Some attempts are being made to exploit the advantages of the properties of these metal tapes, for example, for acoustic devices as shown in U.S. Pat. No. 3,838,365.
An object of the present invention is to employ, for a disk type motor, an amorphous metal tape to form a stator structure which cooperates with a novel permanent magnet rotor which may have an integral flywheel configuration for energy storage purposes.